Add libudev-dev to travis installs so pandajs can build

.travis.yml

@@ -7,14 +7,14 @@ before_install:
   - echo "deb [arch=amd64] https://packages.microsoft.com/repos/azure-cli/ wheezy main" | sudo tee /etc/apt/sources.list.d/azure-cli.list
   - sudo apt-key adv --keyserver packages.microsoft.com --recv-keys 52E16F86FEE04B979B07E28DB02C46DF417A0893
   - sudo apt-get install apt-transport-https
-  - sudo apt-get update && sudo apt-get install azure-cli
+  - sudo apt-get update && sudo apt-get install azure-cli libudev-dev
 #  - yarn global add azure-cli@0.10.x
 
 before_script: yarn netlify-sass
 
 script:
   - yarn test
-  - yarn build 
+  - yarn build
 
 deploy:
   provider: script